DE10047705A1 - Microvalve for controlling fluid flows, has electrostatic comb drive with two comb structures coupled to valve housing and valve element with mutually engaged sets of electrodes - Google Patents

Abstract

The device has at least one valve element (5) with an actuation drive arrangement (12) based on electrostatic principles. The drive arrangement contains at least one so-called comb drive (14a, 14b) with a first comb structure (15) fixed to the valve housing (2) and with a first set of electrodes and a second comb structure (16) coupled to the valve element and with a second set of electrodes engaging the first set of electrodes.

Description

The invention relates to a micro valve for controlling flu flow, with at least one valve member, for its actuation Application based on electrostatic principle propellants are available.

A microvalve of this type is, for example, from the EP 0 485 739 B1. The known micro valve has one Structure in silicon micro technology, with a plate-like Valve member is placed between two housing layers and by two based on electrostatic principle Drives is movable relative to multiple valve openings a suitable control by appropriate positioning to get from fluid flows. Each drive consists of two mutually parallel electrodes on the one hand on the valve member and on the other hand on the valve housing, whereby by creating a Po tentialdifference a positioning force perpendicular to the expansion voltage level of the electrodes is generated, the valve member deflects in the corresponding direction.

A disadvantage of the known microvalve is that it to obtain sufficiently high actuation forces with relative high control voltages must be fed. For sure technical and also for legislative reasons  therefore suitable protective measures are taken, the egg ne further reduction in the size of the microvalve countries. It is therefore the object of the present invention an electrostatically actuated micro valve of the beginning ge called to create that without affecting the he targeted actuation forces a further reduction in Ab allows measurements.

This task is solved by a micro valve whose on based on an electrostatic operating principle medium are characterized in that they have at least one like this Comb Drive Drive included.

Comb-drive drives are usually characterized by two comb structures each taking over an electrode function, which mesh with one another in a similar way to a toothing. When a potential difference is applied, the resulting forces tend to pull the comb structures into one another. A basic explanation of the functioning of the like drives is given in the article "Comb-drive actuators for large displacements", Rob Legtenberg, AW Groeneveld, M. Elwenspoek, J. Micromech. Microeng. 6 ( 1996 ), pages 320-329 or from the article "Electrophysics of Micromechanical Comb Actuators", William A. Johnson, Larry K. Warne, Journal of Microelectromechanical Systems, Vol. 1, March 1995 .

By linking such a comb drive drive with a pneumatic or hydraulic micro valve  the advantage is that within a very compact volume a very large electrode area is made available to anyone that can, which is sufficient even with small control voltages delivers high operating forces to the desired function to ensure the microvalve. This way you don't have to the at the usual higher control voltages necessary protective measures and you can use a microvalve operate easily with voltages that exceed the 60 volt limit not exceed which in the Federal Republic of German country as a limit for the application of the legal low voltage regulation applies. But by that for protective measures required design effort can be reduced, the size of the microvalve can be minimized at the same time ren. In many cases, special control circuits be waived, which are raising the available cause the voltage to a necessary control voltage.

Comb-drive drives were indeed in accordance with the previously mentioned Ar already in connection with micromechanical applications realized. However, like the title of the an article says the production of relatively large actuations supply routes in the foreground, while it is in the inventive The main purpose of the micro valve is to reduce the size adorn. It was therefore not obvious to a specialist to equip a microvalve with a comb-drive actuator.

Advantageous developments of the invention go from the Un claims.  

While the electrodes of the "Comb-drive actua tors for large displacements "described comb structures are finger-shaped, is particularly in one partial construction of the microvalve provided electrodes with to use plate-like shape. The for the generation of the Actuating force required electrode area can thus very large through constructively simple measures the.

In a preferred construction of the microvalve, they are the most Comb structure drive electrodes containing comb structure Ren expediently each as an integral part of the valve member or the valve housing of the microvalve executed. In this context, it is thought of a Shaping from plastic material using injection molding technology take what offers a very large variety of shapes and relative simply with suitable design optimal conditions for offers a fluid power application.

For manufacturing reasons, it would also be possible to separate the comb structures from the associated carrier - on the one hand the valve member and on the other hand the valve housing - to manufacture and fi as a separate unit on this carrier Xieren.

Overall, a realization made of plastic material Advantage that both the  electrical conduction paths as well as the electrode surfaces very much can be easily manufactured.

The microvalve can use MID technology, for example (MOLDED INTERCONNECT DEVICE). That too the LIGA process mentioned can advantageously be used, where a combination of lithography, electroforming and impression technology is used.

For example, the microvalve can only have one comb drive Drive included, but also the simultaneous Realization of several comb drive drives is possible. at A multiple arrangement can be provided for the drives either operate simultaneously to further increase to achieve the actuation forces, or an alternative loading to make an actuation in order to deflect the valve member to actively induce different directions.

Although the microvalve is easily via a valve member can have, whose control movement is a linear translato movement is recommended, the use of the comb Drive actuator especially in combination with a valve construction form, in which the valve member as a control movement Pivots. For this purpose, the valve member on egg be firmly clamped at the end or in particular on a la gerstelle be pivoted like a seesaw, where at least one comb- Drive drive is assigned. Each valve link arm can be one or several Comb Drive drives can be assigned. In the event of  Due to the multiple arrangement, the comb-drive drives can Direction of movement overlap, resulting in further ringing dimensions with an increased power density leads.

To a defined starting position of the valve member shouting, there may be suitable spring means that are effective between the valve member and the valve housing.

To avoid contamination of the electrodes and there due to particularly small gap widths between neighboring ones The comb drive can enable electrode surfaces outside the areas through which the fluid to be controlled flows of the valve housing.

A particularly advantageous construction results with a mic roventil, whose valve member has an elongated shape. Here you can the electrodes of the comb drive are arranged and be aligned so that they are in the longitudinal direction of the valve of the run, making a particularly large effective electric area results.

The drive technology according to the invention can be practically use each microvalve, regardless of the particular one Functionality. For example, the microvalve can be a 3 / 2- Be a directional valve.

The invention based on the accompanying drawing tion explained in more detail. In this show:  

Fig. 1 a first embodiment of the microvalve according to the invention in a schematic representation in a partially sectioned side view looking in the direction of arrow I in FIG. 2,

Fig. 2 is an end view of the microvalve of FIG. 1, partially in section, looking in the direction according to arrow II, in turn, highly schematically,

Fig. 3 shows the microvalve according to FIGS. 1 and 2 in longitudinal section along section line III-III of Fig. 1 and 2 in a schematic representation and

Fig. 4 in one of the Fig. 3 corresponding representation, a detail of a further embodiment of the microvalve, in which the drive means are housed separately from the controlled fluid flows.

The microvalve 1 schematically illustrated in FIGS. 1 to 3 has a valve housing 2 which defines an interior 3 .

In the interior 3 open several the wall of the Ventilge housing 2 penetrating valve channels 4 , which are three valve channels 4 in the exemplary embodiment, since the microvalve is shown here by way of example in the form of a 3/2-way valve. The number of valve channels 4 varies depending on the valve type.

The microvalve 1 is used to control fluid flows, for example hydraulic and preferably pneumatic media. For this purpose, it has at least one and in the exemplary embodiment exactly one valve member 5 , which is accommodated in the interior 3 in a manner that is movable with respect to the valve housing 2 .

The control of the fluid flows takes place in the exemplary embodiment by controlling the flow cross-section provided of two of the valve channels 4 . These are a valve channel 4 designed as a feed channel 4 a and a ventilation channel 4 b. On the other hand constantly communicates the third, c as a working channel 4 formed valve channel 4 with the interior space. 3

The feed channel 4 a and the ventilation channel 4 b each open into the interior 3 with a valve opening 6 a, 6 b. You are expediently surrounded by an annular valve seat 7 .

Each valve opening 6 a, 6 b is opposite a closure section 8 a, 8 b. These closure parts 8 a, 8 b are provided on the valve member 5 . By appropriate movement of the valve member 5 , the distance between the associated valve openings and closure parts 6 a, 8 a; 6 b, 8 b vary, in particular to either release a maximum flow cross section or to completely shut off the valve channel in question. Depending on the configuration, a digital switching function or a continuous control function can be implemented.

In the micro valve 1 designed as a switching valve from the exemplary embodiment, the two valve openings 6 a, 6 b can be alternately opened and closed by actuating the valve member 5 , the respectively released valve opening establishing a fluid connection between the associated feed channel 4 a or ventilation channel 4 b with the working channel 4 c enables to supply a consumer connected to the working channel 4 c with pressure medium or to discharge pressure medium from the latter. The fluid flow takes place through the interior 3 .

To actuate the valve member 5 , drive means 12 based on the electrostatic functional principle are present. Since an electric field is generated by applying a voltage to electrodes lying opposite each other, which produces an actuating force B which is sufficient for switching or moving the valve member 5 . In Fig. 1 dash-dotted two accessible from the outside of the valve housing 2 ago electrical connections 13 can be seen, which can be used ver to apply the required voltage.

The microvalve 1 is characterized, among other things, by the fact that it can be realized with very compact dimensions if required. This is primarily due to the drive means 12 , which in the exemplary embodiment are formed by two comb-drive drives 14 a, 14 b. These have the part before that they can provide a high effective electrode area within a relatively small volume, so that high actuation forces can be realized even with low control voltages. In this way, there is no need for complex electrical protection measures with regard to the electrically conductive components of the microvalve, which in total creates the possibility for small valve dimensions.

The two comb-drive drives 14 a, 14 b of the exemplary embodiment are technically identical, but can have different dimensions as shown, which depends in particular on the location on the valve member 5 .

As can also be seen in particular from FIGS. 2 and 3, each comb-drive drive has a first comb structure 15 fixed to the housing with a family of first electrodes 17 spaced apart from one another and arranged side by side. The electrical 17 protrude from the valve housing 2 in Rich direction to the valve member 5th The valve member 5 in turn is equipped with a second comb structure 16 opposite the first comb structure 15 , which also has a family of second electrodes 18 arranged side by side at a distance from one another. These second electrodes 18 protrude from the valve member 5 towards the wall of the Ventilgehäu ses 2nd

A comb structure is referred to here because, when viewed in the end view according to FIG. 2, there is a comb-like arrangement of the electrodes 17 , 18 .

The two comb structures 15 , 16 of a respective comb-drive drive 14 a, 14 b lie opposite one another in the desired direction of movement 22 of the valve element 5 indicated by the double arrow, with their electrodes 17 , 18 , with the free end ahead, similar mesh with one another without touching each other.

In order to make the electrode surfaces formed by the outer surfaces of the electrodes 17 , 18 as large as possible, the electrodes 17 , 18 are preferably of plate-like design. In a respective comb structure 15 , 16 , the electric electrodes 17 , 18 are arranged so that their main expansion planes 25 , 26 run parallel to one another. At the same time, the main expansion planes of both comb structures 15 , 16 are parallel to one another. The mutual electrode engagement took place in such a way that - apart from the extremely arranged electrode in each case - each electrode of one comb structure engages between two electrodes of the other comb structure.

For reasons of rigidity and better producibility, the shape of the comb structures 15 , 16 can also differ from the one described above, for example beads can be introduced or a slightly wavy structure can be present. It only has to be ensured that the electrode engagement moves in the corresponding tolerance window.

In order to simplify the further explanation, the dash-dotted direction of the electrodes 17 , 18 protruding from the associated valve housing 2 or valve member 5 , which coincides with the desired direction of movement 22, is referred to below as the height direction 27 . This lies in or runs parallel to the main expansion planes 25 , 26 . The comb structures 15 , 16 engage in one another in the height direction 27 of the electrodes 17, 18.

In the exemplary embodiment, the valve member 5 has an elongated shape, the direction of movement 22 extending transversely and in particular at right angles to the longitudinal axis 28 of the valve member 5 . The valve member 5 preferably has a plate-like flat shape with a main extension plane 32 , which is oriented at right angles to the main expansion planes 26 of the electrodes 18 provided on it.

For optimal use of the outline of the valve member 5 , the assigned second comb structure 16 is designed such that its second electrodes 18 also have an elongated shape and extend in the longitudinal direction of the valve member 5 . They are arranged with their one edge-side longitudinal side on the valve member 5 , while the other longitudinal edge faces the first comb structure 15 .

To achieve a further miniaturization of the valve structure Chen, after metallization of the electrode surface They are structured even further by electroplating become.

Both the valve housing 2 and the valve member 5 including the electrode core of the individual electrodes 17 , 18 are preferably made of plastic material, the electrode surfaces 23 , 24 required for the function of the comb-drive drives, as well as preferably the other electrical conductors, by means of metallization of the plastic material are preserved. This creates the possibility, for example, of producing the individual components in a cost-effective manner using a plastic injection molding process, for example using so-called MID technology (MOLDED INTERCONNECT DEVICE). Compared to manufacturing based on silicon technology, this enables a considerable cost reduction.

Alternatively, it would also be conceivable to manufacture under Ver using the so-called LIGA technology Impression technology used in connection with electroplating and Li thography is used.

The electrode surfaces 23 , 24 can be realized particularly easily if the comb structures 15 , 16 are each designed as integral or integral components of the associated valve housing 2 or valve member 5 , as in the exemplary embodiment. Through full-surface metallization of the interior surface 3 of the valve housing 2 delimiting the interior 3 , the complete metallization of the projecting from the wall of the valve housing 2 inwards to the valve member 5 can be achieved first electrodes 17 . In the same way, the desired conductivity of the electrode surfaces 24 provided on the latter can be obtained by full-surface metallization of the outer surface of the valve member 5 including the peripheral surfaces of the second electrodes 18 projecting therefrom.

As an alternative to the above-mentioned integral production of electrodes and valve housing or valve member, it would also be possible to design the electrodes 17 , 18 as separate components and to fix them in a suitable manner on the associated carrier, the valve housing 2 or the valve member 5 . In this context, it would be particularly appropriate to design the respective comb structure 15 , 16 including the associated electrodes 17 , 18 as a structural unit and then fix them to the associated carrier, for example by gluing and / or by inserting them into a correspondingly shaped receptacle (not shown).

The microvalve 1 could have a valve member 5 , the switching movement of which is a purely translatory movement, for example in a manner as is apparent from the aforementioned EP 0 485 739 B1. The valve member 5 could be a diaphragm or plate body movable at right angles to its plane of expansion, the distance from the valve opening to be controlled varies depending on the switching position. It should also be pointed out that, unlike in the exemplary embodiment, the drive means 12 can also have only a single comb-drive drive or more than two comb-drive drives.

The microvalve 1 of the exemplary embodiment is designed so that the switchover movement of the valve member 5 , which can be designated as a control movement, is a swiveling movement. In principle, an arrangement would be conceivable in which the valve member 5 is a bending element that is clamped at one point and can be caused to pivot by the comb-drive drive in the region of its free end. In contrast, the valve member 5 of the embodiment is pivotally mounted on a bearing 33 in the manner of a rocker and has two valve member arms 34 , 35 projecting from the bearing 33 towards opposite sides, which move in the same direction due to the actuation of the valve member 5 .

In the embodiment, it is provided that the tax ble valve openings 6 a, 6 b are on the same long side of the elongated valve member 5 , which consequently also applies to the associated closure parts 8 a, 8 b. The bearing point 33 is, based on the longitudinal axis 28 of the valve member 5 , between the two valve openings 6 a, 6 b. The consequence of this is that when the valve member 5 is actuated, the respective closing part executes a closing movement which approximates the assigned valve opening, while the other closing part carries out an opening movement which moves away from the assigned valve opening.

The valve housing 2 is expediently divided into housing elements 36 , 37 connected to one another in such a way that the two controllable valve openings 6 a, 6 b are provided on one and the same housing element 36 . Since the rotary bearing of the valve member 5 also takes place in the area of the bearing 33 on the same housing element 36 , the distance between a respective valve opening 6 a, 6 b and the associated closure part 8 a, 8 b remains constant even under pressure load on the housing, which is precise Functionality of the micro valve guaranteed.

For pivoting in the exemplary embodiment, for example made of metal and in particular steel existing axle body 42 is provided, on which the valve member 5 is fixed and which is pivotally mounted in the area of the bearing 33 on the valve housing 2 so that the desired axis of rotation 43 defines for the pivoting process becomes. The end of the axle body can be inserted in the joining area between the two housing elements 36 , 37 . It can be a continuously linear axle body or a cranked axle body 42 , as is indicated in FIG. 2. A one-part or multi-part design is possible.

It is advantageous if the axle body 42 is at least partially electrically conductive, so that one of the electrical connections 13 can be connected to it in order to make contact with the second electrodes 18 provided on the valve member 5 . The axle body 42 can be made of suitable metal, for example made of steel, which is encapsulated with plastic material for insulation. However, it would also be conceivable to have an axle body made entirely of plastic material, which is preferably connected in one piece to the valve member 5 .

The drive means 12 are placed in the embodiment so that each valve member arm 34 , 35 is assigned to one of the comb-drive drives 14 a, 14 b. These are arranged and electrically connected such that the actuating force they can exert on the valve member 5 is effective in the same pivoting sense. This is achieved in that the two comb-drive drives 14 a, 14 b are placed on opposite longitudinal sides with respect to the longitudinal axis 28 of the valve member 5 . On each side of the main extension plane 32 is one of the comb drive 14 a, 14 b.

Since the comb-drive drives 14 a, 14 b can thus only exert an actuating force in one actuation direction, spring means 44 are additionally provided which bias the valve member 5 into an initial position. The spring means 44 we ken between the valve member 5 and the valve housing 2 and generate a restoring force which is opposite to the actuating force of the comb-drive drives 14 a, 14 b. It would be possible to combine the spring means 44 with the axle body 42 and to form this, for example, in the manner of a torsion spring.

It would also be conceivable to place and design the comb-drive drives 14 a, 14 b in such a way that the actuating forces which can be generated by them act in opposite pivoting directions on the valve member 5 . This can be achieved, for example, in that both comb-drive drives 14 a, 14 b are placed on the long side of the valve member 5 , while they continue to cooperate with different ones of the two valve members 34 , 35 . An alternative actuation would then be possible in order to select one of two switch positions. In such a case, separate spring means could be dispensed with, although these are always recommended in order to ensure a defined starting position, even in the deactivated state of the electrostatically active drive means 12 .

To operate the microvalve 1 , an electrical voltage is applied to the first and second electrodes 17 , 18 of the two comb structures 15 , 16 , the potential difference causing the formation of electric fields between the respective opposite electrode surfaces 23 , 24 . The resulting, perpendicular to the main expansion planes 25 , 26 effective forces equalize or are at least partially compensated for by the fact that the valve member 5 on the valve housing 2 is fixed immovably in the axial direction of the axis of rotation 43 . In addition, the electric fields also cause actuation forces B, which are effective in the above-mentioned height direction 27 and seek to pull the two comb structures 15 , 16 into one another with the free electrode ends. These forces are the actuating forces relevant to the actuation of the valve member 5 in the present case. They are relatively large in relation to the volume occupied by the electrodes 17 , 18 , which is caused by the relatively large effective electrode areas 23 , 24 . In this way, high actuating forces can be generated despite the small size.

In the embodiment of FIGS. 1 to 3, the comb-drive drives 14 a, 14 b are also flowed around by the fluid flowing through the valve housing 2 . In the case of an embodiment indicated in FIG. 4, this is not the case since the existing comb drive drives are accommodated outside the regions of the valve housing 2 through which the fluid to be controlled flows. In this way, an impairment of the function of the comb drive drives is prevented.

In the embodiment according to FIG. 4, the components corresponding to the other embodiment are provided with the same reference numerals. However, it can be seen here that the valve member 5 is divided into a control section 45 and an actuation section 46 , the control section 45 carrying the closure parts 8 a, 8 b and the comb-drive drives 14 a, 14 b being assigned to the actuation section 46 . An inside the valve housing 2 provided partition 47 divides the interior 3 fluid-tight into a actuation supply chamber 48 and a control chamber 49 , the Steuerab section 45 in the control chamber 49 and the actuation section 46 is housed in the actuation chamber 48 .

The comb-drive drives 14 a, 14 b are in the actuation supply chamber 48 and cooperate with the actuating section 46 of the valve member 5 . All valve channels 4 open into the control chamber 49 , so that the actuation chamber 48 is sealed off from the fluid flows in a fluid-tight manner.

In the exemplary embodiment, the control section 45 consists of an end section of the axle body 42 , which rotatably passes through the partition wall 47 with a seal. The axle body 42 carries at circumferentially offset locations, the closure parts 8 a, 8 b, which are shown in broken lines in FIG. 4, because they are on the circumferential side of the axle body 42 facing away from the viewer. The valve parts 8 a, 8 b facing these Ver are covered in Fig. 4 by the axle body 42 and are therefore not visible.

As regards the exemplary embodiments, it can be summarized once again that these are microvalves, which are in particular based on MID technology and have electrostatic actuators with one or more comb-drive drives. The pivoting speed of the valve member 5 results in a type of rocker construction, the valve member being able to have integrated electrode comb structures. The rocker (valve member) is in particular made of completely metallizable plastic material that can be manufactured using injection molding technology. The sealing force in the rocker arrangement is generated using the existing lever arms, with optimal force relationships resulting from the fact that the distance between the closure parts 8 a, 8 b from the axis of rotation 43 is less than that of the force introduction center of the comb drive drives 14 a, 14 b.

The microvalve can be used, for example, for a pressure range be designed up to 10 bar. Due to the advantageous type drive technology, it can be operated with low control voltages operate, for example with 24 volts or 48 volts, with in any case, an upper limit of a maximum of 60 volts can be observed is to be able to dispense with complex protective measures.

The metallization of the associated components can be galva niche.

Are the electrodes on the one hand in the valve housing and on the other others integrated into the valve member can be a very exact Manufacturing can be guaranteed what when assembling the Ven tils enables the realization of very small gap distances. Are the required minimum gap distances by spray Casting technology not easily feasible, can be done by electroplating correspondingly high metal layer thicknesses of the desired small gap distance can be realized. The little electric denabstand again has the advantage that only small switching tensions are required.

The electrostatic drive technology is in one area separated from the fluid streams becomes contaminated  counteracted the electrodes, the relative Could impair mobility.

Claims (18)

1. Micro valve for controlling fluid flows, with at least one valve member ( 5 ), for its actuation based on electrostatic functional principle drive means ( 12 ) are present, characterized in that the Antriebsmit tel at least one so-called comb-drive drive ( 14 a , 14 b) included. 2. Micro valve according to claim 1, characterized in that the comb-drive drive ( 14 a, 14 b) a housing-fixed to the valve housing ( 2 ) of the microvalve, a family of first electrodes ( 17 ) having first comb structure ( 15 ) and has a second comb structure ( 16 ) which is coupled to the valve member ( 5 ) and has a family of second electrodes ( 18 ), the two comb structures ( 15 , 16 ) engaging with one another with their electrodes ( 17 , 18 ). 3. Microvalve according to claim 2, characterized in that the electrodes ( 17 , 18 ) have a plate-like shape, the main expansion planes ( 25 , 26 ) of all electrodes ( 17 , 18 ) running parallel to one another. 4. Micro valve according to claim 2 or 3, characterized in that the first comb structure ( 15 ) as a separate unit o which is preferably formed as an integral part of the Ventilgehäu ses ( 2 ). 5. Microvalve according to one of claims 2 to 4, characterized in that the second comb structure ( 16 ) is designed as a separate unit or preferably as an integral part of the valve member ( 5 ). 6. Micro valve according to one of claims 1 to 5, characterized in that the valve member ( 5 ) and / or the valve housing ( 2 ), preferably including the comb structures ( 15 , 16 ) of the at least one comb-drive drive from at least partially metallized plastic material. 7. Micro valve according to one of claims 1 to 6, characterized by a valve housing ( 2 ) and / or valve member ( 5 ) realized in MID technology or in LIGA technology. 8. Micro valve according to one of claims 1 to 7, characterized in that the drive means ( 12 ) contain a plurality of comb-drive drives which can produce an actuating force for the valve member ( 5 ) simultaneously or alternately. 9. Microvalve according to one of claims 1 to 8, characterized in that the valve member ( 5 ) is designed and arranged such that its control movement caused by the drive means ( 12 ) is a pivoting movement. 10. Micro valve according to claim 9, characterized in that the valve member ( 5 ) at a bearing point ( 33 ) is pivotally mounted in the manner of a rocker, at least one of the valve member arms ( 34 , 35 ) having a comb drive ( 14 a, 14 b) is assigned. 11. Micro valve according to claim 10, characterized in that two valve member arms ( 34 , 35 ) each have at least one comb drive drive ( 14 a, 14 b) is assigned. 12. Micro valve according to claim 11, characterized in that the two comb-drive drives ( 14 a, 14 b) with respect to the longitudinal axis ( 28 ) of the valve member ( 5 ) on opposite longitudinal sides of the valve member ( 5 ). 13. Micro valve according to one of claims 9 to 12, characterized in that the valve member ( 5 ) has at least one with a valve opening to be controlled ( 6 a, 6 b) cooperating closure part ( 8 a, 8 b), the distance from the center of the Swivel movement is less than that of the center of the comb drive ( 14 a, 14 b). 14. Micro valve according to one of claims 1 to 13, characterized in that spring means ( 44 ) are present which bias the valve member ( 5 ) in the direction of an initial position before. 15. Micro valve according to one of claims 1 to 14, characterized in that the at least one comb-drive drive ( 14 a, 14 b) is arranged outside the regions of the valve housing ( 2 ) through which the fluid to be controlled flows. 16. Micro valve according to claim 15, characterized in that the valve member ( 5 ) has a control section ( 45 ) and an actuating section ( 46 ), the control section ( 45 ) with at least one valve opening to be controlled ( 6 a, 6 b) and Actuating section ( 46 ) cooperates with the at least one comb drive drive ( 14 a, 14 b) and the two sections ( 45 , 46 ) including the respectively assigned valve opening ( 6 a, 6 b) and the comb Drive drive ( 14 a, 14 b) are arranged in separate chambers ( 48 , 49 ) of the valve housing ( 2 ). 17. Micro valve according to one of claims 1 to 16, characterized in that the valve member ( 5 ) has an elongated shape, the electrodes ( 17 , 18 ) of the comb-drive drive ( 14 a, 14 b) expediently in the longitudinal direction of the valve member des ( 5 ) run. 18. Micro valve according to one of claims 1 to 17, characterized is designed as a 3/2-way valve.